BroadcastReceiver triggered to update another Activity - android-studio

Question

I am trying to make a feature as part of my android app, where a user interacts with a geofence based on their location on a map and it will fire up a dialog telling the user they are near the starting point of the route using a BroadcastReceiver in its own class.
So far I can trigger it and provide Toast messages, but I can't seem to use it to trigger a UI change in my other activity.
Here is my BroadcastReceiver class -
public class GeofenceBroadcastReceiver extends BroadcastReceiver {
private static final Object TAG = "Error";
#Override
public void onReceive(Context context, Intent intent) {
GeofencingEvent geofencingEvent = GeofencingEvent.fromIntent(intent);
if (geofencingEvent.hasError()) {
Log.d("TOASTY", "onReceive: Geofence even has error..");
}
List<Geofence> triggeredGeofenceList = geofencingEvent.getTriggeringGeofences();
for (Geofence geofence : triggeredGeofenceList) {
Log.d("GEOF", "onReceive: "+geofence.getRequestId());
}
Location triggerLocation = geofencingEvent.getTriggeringLocation();
double lat = triggerLocation.getLatitude();
double lon = triggerLocation.getLongitude();
Toast.makeText(context, "GEOFENCE TRIGGERED AT : LAT IS :" + lat + " LON IS : " +lon, Toast.LENGTH_SHORT).show();
int transitionType = geofencingEvent.getGeofenceTransition();
switch (transitionType) {
case Geofence.GEOFENCE_TRANSITION_ENTER:
Toast.makeText(context, "Entered Geofence", Toast.LENGTH_SHORT).show();
Log.d("GEOF", "onReceive: "+geofencingEvent.getGeofenceTransition());
break;
case Geofence.GEOFENCE_TRANSITION_DWELL:
Toast.makeText(context, "Dwelling inside of Geofence", Toast.LENGTH_SHORT).show();
break;
case Geofence.GEOFENCE_TRANSITION_EXIT:
Toast.makeText(context, "Exited Geofence area", Toast.LENGTH_SHORT).show();
break;
}
Bundle b = intent.getExtras();
Intent i = new Intent(context, routeActivity.class);
i.putExtra("lat", lat);
i.putExtra("lon", lon);
i.putExtras(b);
Log.d("LOLCALLY", "onReceive: "+i);
context.sendBroadcast(i);
}
}
My thinking was to use intent, I have tried to pull the triggered location (which I can see is correct in the log output) into my other activity but no joy.
Many thanks!

Answer 1

You need to register your receiver on your activity and process its callback:
public class MyActivity extends AppCompatActivity {
private BroadcastReceiver geofenceReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
// Pull triggered location and use it to update the activity
}
};
#Override
protected void onResume() {
super.onResume();
registerReceiver(geofenceReceiver, new IntentFilter("YOUR_GEOFENCE_ACTION"));
}
#Override
protected void onPause() {
super.onPause();
unregisterReceiver(geofenceReceiver);
}
}